This project has been undertaken to study various aspects of cell locomotion, including the mathematical basis of macroscopic assays for leukocyte chemotaxis. Procedures for measuring parameters of cell migration, e.g., computer assisted tracking techniques, have been developed. Recent emphasis has been on perfecting laser quasielastic light scattering techniques for nonperturbative measurements of the mechanical properties of soft protein gels which, when examined by conventional rheometers, are structually unstable (cf. project Z01 CT 00021-11 PSL). The objective is to examine cytoplasmic extracts from motile cells, in order to understand how the polymerization of cytoskeletal networks and the generation of contractile force therein actually takes place. In order to gain practical experience in acquiring such data, various measurements have been performed on polymer networks formed from data, various measurements have been performed on polymer networks formed from fibrin, which in many aspects is a similar but more readily available material.